This invention relates to a water level detecting device for a percolator, particularly to one provided in a pot body with a buoy able to move upward and downward together with the height of the water level of the water reservoir of the pot body. When the water level reaches a lowermost limit preset, the water level detecting device will properly interact with the buoy to disconnect the electric source of the heater of the pot body, enabling the percolator to cut off electricity automatically to enhance safety in use.
A first conventional percolator disclosed in a Taiwan patent of No. 168846 includes a water container, a loading funnel, and a pot and a lid.
The water container has its upper outer wall formed with male threads and its upper inner edge formed with an engage edge.
The loading funnel positioned in the water container is formed with a projecting edge at the upper end, and provided with a tube at the lower side. The loading funnel is positioned in the interior of the container having a holding disk bored with numerous filtering pores.
The pot assembled on the water container has its bottom formed with a recessed chamber, which has its inner wall provided with female threads. The pot is further provided in the intermediate portion with a duct passing through the recessed chamber and having slots in the upper side, and the recessed chamber is provided inside with a filter screen and a washer. The lid is covered on the pot.
After the water container is filled with water, and coffee powder is filled in the holding disk inside the loading funnel and the pot is threadably combined with the water container, the water container has its lower side heated to boil the water inside. When the water in the water container boils, pressure produced in the water container will force the boiling water into the loading funnel to mix with the coffee powder in the holding disk through the siphon tube under the loading funnel. Then, the boiling water mixed with the coffee powder is filtered by the filter screen in the recessed chamber of the pot, and the coffee liquid is led by the duct of the pot to flow into the pot through the upper slots of the duct, thus obtaining aromatic coffee. In general, the first conventional percolator is small in size, convenient to be carried about, and easy to be disassembled for cleaning.
A second conventional percolator disclosed in a Taiwan patent of No. 134874, includes a glass pot, a potholder and a sensing device.
The glass pot has its lower side threadably assembled with a heating disk having its circumferential edge provided with an annular projecting edge extending downward.
The potholder has its upper base protrusively provided with a plurality of heat-insulating rings spaced apart properly. Each heat-dispersing ring is bored with a plurality of heat-radiating holes spaced apart. An arc-surfaced heat-insulating plate is positioned above the heat-insulating rings and an electric heating disk is fixed on the heat-insulating plate, having at least one electric heating tube controlled by a driving circuit. The electric heating disk has its lower side connected with a first sensing unit for sensing the temperature of the electric heating disk. Further, the upper base of the potholder is provided inside with a fixing plate for positioning the electric heating disk.
Further, a second sensing unit is provided for sensing the temperature of water in the pot so as to maintain the original taste of coffee brewed in the pot.
A third conventional percolator disclosed in a Taiwan patent of No. 114331, includes a heat-conducting disk, a water-stopping annular plate, a metal fixing disk, an electric heating switch, an overheat protection device and an electric indicating lamp.
The heat-conducting disk has a U-shaped heating ring provided inside and two electric studs extending downward from the lower side. Further, the heat-conducting disk has its center and its tri-sectioned circumferential edge respectively provided with a stud with a fixing threaded hole, and beside the central fixing threaded hole is provided a power adjusting entrance terminal of a stud shape with a threaded hole.
The metal fixing disk is bored with fixing holes, wide holes and annular holes for matching with the fixing threaded holes of the heat-conducting disk. In assembling, the heat-conducting disk is assembled on the lower side of a pot by means of the water stopping annular plate. So the heat conducting disk has its surface closely contacting with the circumferential surface of an assembly hole, and the threaded holes under its bottom pass through the assembly hole respectively facing the fixing holes of the fixing disk so that the electric heating switch and the overheat protection device can be fixed on both the fixing disk and the heat conducting disk.
A fourth conventional percolator shown in FIG. 1 includes a pot body 1 provided with a coffee powder container 10 on the topside and a heater 12 on the bottom wall 11. When the heater 12 is powered, it begins to boil the water in the water reservoir of the pot body for brewing coffee.
The conventional percolators described above all have the water levels of their water tank able to be checks by a user""s eyes. Under the circumstances, if the water level of the water tank reaches a lowermost limit or the water therein is dried up, but the user should not pay attention to the situation, the percolator might be burned idly, liable to cause danger.
The objective of the invention is to offer a water level detecting device for a percolator, provided with an electric heating sensing device able to detect the water level of the percolator and enable an electric heating film to be cut off electrically and automatically.
The features of the invention are described as follows.
1. The water level detecting device for a percolator in the present invention includes a pot body and a detecting device. The pot body is provided with a coffee powder container on the topside and a buoy device in the interior. The buoy device consists of a buoy rod fitted thereon with a buoy. The detecting device (a magnetic induction element or a photoelectric element) is provided on a power base or on the outer wall of the pot body or in the buoy rod. The buoy in the pot body will move upward or downward together with the height of the water level of a water tank. When the water level of the water tank reaches a lowermost limit preset, the detecting device will properly interact with the buoy to disconnect the power of the heater of the pot body, enabling the percolator to cut off electricity automatically.
2. The buoy of the pot body is provided with a magnetic member.
3. The buoy rod of the pot body is provided inside with a receiving element or emitting element of a photoelectric element.
4. The magnetic induction element of the detecting device is a magnetic reed switch or a HALL IC.
5. The photoelectric element of the detecting device is a ultra-red ray emitting/receiving element or a light sensitive resistor or a photoelectric transistor.